org.oreodata.predicates
Class Predicate

java.lang.Object
  |
  +--org.oreodata.predicates.Predicate

All Implemented Interfaces:

RecordFilter, java.io.Serializable

Direct Known Subclasses:

CompoundPredicate, SimplePredicate

public abstract class Predicate

extends java.lang.Object

implements RecordFilter

Abstract base class for database query predicates.

See Also:

Serialized Form

Field Summary

protected Predicate

complement

Constructor Summary

Predicate()

Method Summary

abstract boolean	accept(Record x0) Does this record meet the filter criterion?
abstract Predicate	getComplement()
abstract java.lang.String	recType() says what kind of record type we are looking for, i.e.
abstract java.lang.String	sqlEquivalent()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

complement

protected Predicate complement

Constructor Detail

Predicate

public Predicate()

Method Detail

getComplement

public abstract Predicate getComplement()

sqlEquivalent

public abstract java.lang.String sqlEquivalent()

Specified by:

sqlEquivalent in interface RecordFilter

Returns:

The SQL SELECT command that is the equivalent to this. A null value would indicate that we don't know the SQL command. In that case, the filter will have to be applied in-memory.

recType

public abstract java.lang.String recType()

Description copied from interface: RecordFilter

says what kind of record type we are looking for, i.e. the filter will only return results of a certain record type. If this returns null, it means that we could have heterogeneous results.

Specified by:

recType in interface RecordFilter

accept

public abstract boolean accept(Record x0)

Description copied from interface: RecordFilter

Does this record meet the filter criterion?

Specified by:

accept in interface RecordFilter